I put the link to download the Microsoft Active Directory Topology Diagrammer.

With the Active Directory Topology Diagrammer tool, you can read your Active Directory structure through LDAP. The Active Directory Topology Diagrammer tool automates Microft Office Visio to draw a diagram of the Active Directory Domain topology, your Active Directory Site topology, your OU structure, your DFS-R topology or your current Exchange 20XX Server Organization. With the Active Directory Topology Diagrammer tool, you can also draw partial Information from your Active Directory, like only one Domain or one site. The objects are linked together, and arranged in a reasonable layout that you can later interactively work withthe objects in Microsoft Office Visio.

To verify if the AD replication (RFS) is working fine on the DC you can try with these examples:

Execute the following command on a cmd: repadmin /showreps

Execute the following command on a cmd: repadmin /replsum /bysrc /bydest /sort:delta

All domain controllers should show 0 in column “Fails”, and “Deltas” longer (indicating the time since the last synchronization) must be less than or at most equal to the time of replication used in the Site -Link domain Controller (30 minutes).